scholarly journals Studies on the cathepsins in elastic cartilage

1969 ◽  
Vol 112 (4) ◽  
pp. 427-433 ◽  
Author(s):  
S. Y. Ali ◽  
Lois Evans
Keyword(s):  
Acid Phosphatase ◽  
Dna Content ◽  
Quantitative Method ◽  
Cathepsin C ◽  
Elastic Cartilage ◽  
Fixed Weight ◽  
Cathepsin Activity ◽  
Rabbit Ear ◽  
Ear Cartilage ◽  
Hydrolysis Of

1. The presence of several enzymes in rabbit ear cartilage was examined by a quantitative method that permits the incubation of a fixed weight of cartilage sections (18μm.) with an appropriate exogeneous substrate. 2. As the presence of cathepsins B and D in cartilage has already been established, evidence is now provided to show that cathepsins A and C are also present and are maximally active at pH5. 3. Cathepsin A was recognized by its hydrolysis of benzyloxycarbonyl-glutamyl-tyrosine and cathepsin C by its hydrolysis of glycyl-tyrosine amide; the cartilage also hydrolysed benzyloxycarbonyl-glutamyl-phenylalanine and benzoyl-dl-phenylalanine 2-naphthyl ester at pH5. 4. The acid phosphatase activity and the DNA content of cartilage have also been measured to provide a basis for comparison with the cathepsin activity of cartilage obtained from other sites and species.

scholarly journals Characterization of cathepsins in cartilage

1967 ◽  
Vol 105 (2) ◽  
pp. 549-557 ◽  
Author(s):  
S. Y. Ali ◽  
L. Evans ◽  
E. Stainthorpe ◽  
C. H. Lack
Keyword(s):  
Cathepsin B ◽  
Cartilage Matrix ◽  
Heat Inactivation ◽  
Ph Values ◽  
Fixed Weight ◽  
Exogenous Substrate ◽  
Nitrophenyl Phosphate ◽  
Rabbit Ear ◽  
Ear Cartilage

The presence of a cathepsin B-like enzyme in rabbit ear cartilage was established by the use of the synthetic substrates benzoyl-l-arginine amide and benzoyl-dl-arginine 2-naphthylamide. This was facilitated by using a technique that permits the incubation of a fixed weight of thin (18μ) cartilage sections with an appropriate exogenous substrate. The enzymic properties of cathepsin B in cartilage have been compared with an endogenous enzyme that liberates chondromucopeptide by degrading the cartilage matrix autocatalytically at pH5. Besides being maximally active at pH4·7, these cartilage enzymes are enhanced in activity by cysteine and inhibited by arginine analogues, iodoacetamide, chloroquine and mercuric chloride. They are not inhibited by EDTA, di-isopropyl phosphorofluoridate and diethyl p-nitrophenyl phosphate. When inhibiting the release of chondromucopeptide from cartilage at pH5, the arginine-containing synthetic substrates are hydrolysed simultaneously. These enzymes also share the same heat-inactivation characteristics at various pH values, being stable at acid pH and unstable at neutral and alkaline pH. The experimental evidence indicates that a cathepsin B-like enzyme may be partly responsible for the autolytic degradation of cartilage matrix at pH5.

scholarly journals STUDIES ON CARTILAGE

1960 ◽  
Vol 8 (1) ◽  
pp. 151-163 ◽  
Author(s):  
Huntington Sheldon ◽  
Robert A. Robinson
Keyword(s):  
Amorphous Material ◽  
Surface Membrane ◽  
Electrophoretic Pattern ◽  
Elastic Component ◽  
Elastic Tissue ◽  
Cell Cytoplasm ◽  
Elastic Cartilage ◽  
Rabbit Ear ◽  
The Matrix ◽  
Ear Cartilage

Electron microscope observations on rabbit ear cartilage following the administration of papain show that both the elastic component of the matrix and the amorphous material disappear leaving a matrix which consists of delicate fibrils which are presumed to be collagen. This unmasking of fibrils coincides with the appearance of an abnormal component in the electrophoretic pattern of the rabbit's serum. The chondrocytes show vacuoles in their cytoplasm which appear at the same time that the cells appear crenated in the light microscope. A ruffly appearance of the cell surface membrane coincides with this vacuolization, and vacuoles often appear open and in continuity with the extracellular space. The resurgence of the rabbit ear is accompanied by a reconstitution of both the amorphous material and the elastic component of the matrix. During this period numerous dilated cisternae of the endoplasmic reticulum which contain a moderately dense material are present in the chondrocyte cytoplasm. We have been unable to demonstrate a direct relationship between the elastic component of the matrix and a particular component of the chondrocyte cytoplasm, but it is clear that changes occur in the cartilage cell cytoplasm during both the depletion and reconstitution of the matrix. Previous studies on the effect of papain on elastic tissue are noted and the possible relationships between changes in the cells and matrix of this elastic cartilage are discussed.

scholarly journals Phosphatase synthesis in Klebsiella (Aerobacter) aerogenes growing in continuous culture

1972 ◽  
Vol 127 (1) ◽  
pp. 87-96 ◽  
Author(s):  
P. G. Bolton ◽  
A. C. R. Dean
Keyword(s):  
Alkaline Phosphatase ◽  
Acid Phosphatase ◽  
Continuous Culture ◽  
Activity Profile ◽  
Glucose Effect ◽  
Ph Values ◽  
Nitrophenyl Phosphate ◽  
Wide Range ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of

1. Phosphatase synthesis was studied in Klebsiella aerogenes grown in a wide range of continuous-culture systems. 2. Maximum acid phosphatase synthesis was associated with nutrient-limited, particularly carbohydrate-limited, growth at a relatively low rate, glucose-limited cells exhibiting the highest activity. Compared with glucose as the carbon-limiting growth material, other sugars not only altered the activity but also changed the pH–activity profile of the enzyme(s). 3. The affinity of the acid phosphatase in glucose-limited cells towards p-nitrophenyl phosphate (Km 0.25–0.43mm) was similar to that of staphylococcal acid phosphatase but was ten times greater than that of the Escherichia coli enzyme. 4. PO43−-limitation derepressed alkaline phosphatase synthesis but the amounts of activity were largely independent of the carbon source used for growth. 5. The enzymes were further differentiated by the effect of adding inhibitors (F−, PO43−) and sugars to the reaction mixture during the assays. In particular, it was shown that adding glucose, but not other sugars, stimulated the rate of hydrolysis of p-nitrophenyl phosphate by the acid phosphatase in carbohydrate-limited cells at low pH values (<4.6) but inhibited it at high pH values (>4.6). Alkaline phosphatase activity was unaffected. 6. The function of phosphatases in general is discussed and possible mechanisms for the glucose effect are outlined.

Further Observations upon the Oxyntic Cells with Special Reference to Acid Phosphatase

1952 ◽  
Vol s3-93 (23) ◽  
pp. 259-268
Author(s):  
GORDON MENZIES
Keyword(s):  
Acid Phosphatase ◽  
Special Reference ◽  
Single Injection ◽  
Central Area ◽  
Basal Part ◽  
Prolonged Starvation ◽  
Apparent Change ◽  
Multiple Doses ◽  
Hydrolysis Of ◽  
In Cells

1. In continuation of work already reported (Menzies, 1949) further data are presented on the structure and cyto-chemistry of the granules in the oxyntic cells of the rat's stomach. 2. After multiple doses of pilocarpine or histamine, and after feeding, the phospholipine (as shown by acid haematein) is shed from some or all of the granules. The lipine first leaves the granules in cells situated in the basal part of the tubules, and finally those in the neck of the tubules, but a non-lipine lipoid remains in all the granules (as shown by sudan black). 3. The granules enlarge after prolonged starvation as they do after a single injection of pilocarpine; but after extraction of lipoids by hot pyridine and subsequent straining with iron haematoxylin, enlargement (i.e. of the non-lipoid moiety) is shown only after prolonged starvation. 4. A light, uncoloured central area is found in some of the largest granules after feeding and colouring with acid haematein. 5. An acid phosphatase appears in the oxyntic cells whose granules are about to lose their lipine component, and it disappears when they have done so. It is suggested that the acid phosphatase may cause hydrolysis of the phospholipine. 6. Only after prolonged starvation is there any apparent change in granule numbers, when they are decreased.

Recent findings in oogenesis of Drosophila melanogaster

Development ◽  
1977 ◽  
Vol 39 (1) ◽  
pp. 45-57
Author(s):  
F. Giorgi ◽  
J. Jacob
Keyword(s):  
Drosophila Melanogaster ◽  
Acid Phosphatase ◽  
Ovarian Development ◽  
Superficial Layer ◽  
Blood Proteins ◽  
Selective Hydrolysis ◽  
Internal Lining ◽  
Hydrolysis Of ◽  
Zinc Iodide ◽  
Yolk Platelet

The role played by the vitellogenic oocytes of Drosophila melanogaster in relation to the elaboration of material taken from the haemolymph is examined by ultrastructural cytochemistry. As revealed by the Gomori procedure, acid phosphatase occurs widely over the forming yolk platelets of the cortical and central ooplasm. A number of Golgi apparatuses in thecortical ooplasm are also positively stained with lead precipitates. With the proceeding of the ovarian development it becomes progressively more difficult to demonstrate cytochemically the enzyme over the yolk platelets. In stage 9–10 chambers the acid phosphatase is restricted to the so-called associated body, while the rest of the yolk platelet appears devoid of lead deposits. By using a osmium zinc iodide (OZ1) complex as a preferential staining method for the Golgi apparatus, it has been shown that, apart from the apparatus itself, a number of OZI deposits occur over the superficial layer of the forming yolk platelets. When mature yolk platelets are formed at later stages, the OZI deposits in the yolk platelets come to be restricted to the cap-like region of the superficial layer which contains the associated body. In vitellogenic oocytes, both the internal lining of the limiting membrane of the forming yolk platelets and the associated body of the mature yolk platelets react positively, to cytochemical methods to demonstrate carbohydrates. The present findings are interpreted as indicating the involvement of lysosomal enzymes in the process of maturation of the yolk material. The suggestion is also made that such an involvement is required to accomplish a selective hydrolysis of those blood proteins which have been taken in by vitellogenic oocytes along with yolk precursors.

Biochemical characterization of the tartrate-resistant acid phosphatase of human spleen with leukemic reticuloendotheliosis as a pyrophosphatase.

1977 ◽  
Vol 23 (1) ◽  
pp. 89-94 ◽  
Author(s):  
K W Lam ◽  
L T Yam
Keyword(s):  
Acid Phosphatase ◽  
Biochemical Characterization ◽  
Normal Animal ◽  
Tartrate Resistant Acid Phosphatase ◽  
Animal Tissues ◽  
Human Spleen ◽  
Optimal Activity ◽  
Catalytic Function ◽  
Hydrolysis Of

Abstract A tartrate-resistant acid phosphatase was isolated from a human leukemic spleen by freeze-thawing in saline and purified by repeated chromatography on carboxymethyl-cellulose. The purified enzyme has a molecular weight of 64 000. It catalyzes the hydrolysis of inorganic and organic pyrophosphate as well as the phenolic ester of monoorthophosphate, with optimal activity between pH 5 and 6. However, there is no activity toward mono-orthophosphate esters of aliphatic alcohols. The present data have identified its catalytic function as a pyrophosphatase. However, it has properties different from the pyrophosphatase previously observed in normal animal tissues.

Enhancing Effect of Surfactant and Protein on Hydrolysis of Thymolphthalein Monophosphate by Purified Prostatic Acid Phosphatase

1975 ◽  
Vol 21 (12) ◽  
pp. 1761-1765 ◽  
Author(s):  
Andras G Foti ◽  
Harvey Herschman ◽  
J Fenimore Cooper ◽  
Hedi imFeld
Keyword(s):  
Acid Phosphatase ◽  
Serum Proteins ◽  
Gradient Centrifugation ◽  
Gel Filtration ◽  
Prostatic Acid Phosphatase ◽  
Sucrose Density Gradient ◽  
Sucrose Density Gradient Centrifugation ◽  
Brij 35 ◽  
Hydrolysis Of ◽  
Protein Bovine Serum Albumin

Abstract Purified prostatic acid phosphatase catalyzes the hydrolysis of thymolphthalein monophosphate 10-fold faster if an optimal concentration of Brij 35 (a wetting agent) or protein (bovine serum albumin or human serum proteins) is present. Results of gel filtration, dialysis, and sucrose density-gradient centrifugation analysis suggest that the substrate must combine with detergent or protein before the enzyme can catalyze its hydrolysis.

Intracellular Lipids in Rabbit Ear Cartilage during Tissue Regeneration

1986 ◽  
Vol 127 (4) ◽  
pp. 249-254 ◽  
Author(s):  
J. Labandeira-Garcia ◽  
M. Guerra -Seijas
Keyword(s):  
Tissue Regeneration ◽  
Intracellular Lipids ◽  
Rabbit Ear ◽  
Ear Cartilage
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